Air and oil preheating system for burners



March 23, 1954 TRAUB 2,672,925

AIR AND OIL PREHEATING SYSTEM FOR BURNERS Filed May 9, 1950 2 Sheets-Sheet 2 FIG.4

IN V EN TOR.

Patented Mar. 23, 1954 OFFICE I AIR AND OIL PREHEATING SYSTEM FOR BURNERS Paul Traub, Brooklyn, N. Y.

Application May 9, 1950, Serial No. 160,884

7 Claims.

The general object of this invention is to produce an efficient oil burner in which the air serving one or more burners will be preheated to a desired degreeto aid combustion and be so routed prior to reaching the burners that it will to a maximum degree serve to preheat and desirably reduce the viscosity of the oil furnished to the sameburners.

A feature of the invention resides in employing a supply of heated air in two courses, first, to an oil preheater for the purpose of desirably raising the temperature of the oil supp-lied to one or more burners and second, to each burner for the purpose of more readily atomizing the heated oil pumped thereto.

Another feature of the invention resides in providing an arrangement operative responsive to variations in oil temperature in an oil preheater so that upon a rise in temperature in the oil preheater above a predetermined upper limit, the heated air to the preheater will be ,cut off and all preheated air routed exclusively to the burners. However, upon a drop in temperature in the preheater to a safe predetermined level,

the hot air will again be routed to the oil preheater for desirably raising the temperature of oil furnished the burners.

Another feature of the invention resides in 2 providing a simple control which will enable air and oil in desirable measure to be used most effectively, with excess thereof bled from the system, and. reused.

A further feature resides in utilizing most effectively preheated oil for promoting efiicient combustion and for creating desirable heat in-,

nected to the burner, means for supplying oil from the reservoir to the burner, means for preheating air, means for passing the preheated air in a first path in heat exchange relation with the oil and then to the burner, and means for passing the preheated air in a secondpath direct to the burner. Preferably, oil passing to. the

reservoir is preheated by thepreheated air while simultaneously oil, in the reservoir is heated by the same air. A control responsive to temperature of oil leaving the reservoir automatically selects the path of travel of preheated air.

The attached drawings illustrate a preferred embodiment of the invention, in which Figure 1 is a plan view of one portion of the system showing, in part, the air and oil supply routes serving the system; Figure 2 is a sectional view illustratin applicants system combining his oil preheater and arrangement wherein preheated air is employed in combination therewith;

Figure 3 is a view in end elevation showing a detail of applicants control system for regulating I the routing of air through his heat exchangeror alternately directly to his burners; and

Figure 4 is a sectional view taken on line IVIV of Figure 2, illustrating the reverse side' of the arrangement shown in Figure 3.

Considering the drawings, similar designations.

referring to similar parts, the figures are directed more particularly to applicants burner, oil feed, and oil heating arrangement adapted to be positioned for service at the boiler. Of course, it will be understood that the oil storage tank, feed lines and auxiliary equipment will normally be installed as desired outside the boiler itself.

Numeral 5 designates an air intake leading to an air heat exchanger 6. The air is in the ordinary manner furnished to the heat exchanger by a blower not shown. The heat exchanger is suitably positioned within a fire box of the boiler served by the system. For purposes of illustration, the fire box is fragmentarily illustrated by the dash-dot enclosure shown in Figure 3.

The air heat exchanger provides a tortuous passage for the air so that it may rapidly be raised in temperature in its passage through the exchanger. Preferably, an inner tube 1 conducts the air from the intake to a series of outer passages 8, whereupon the air is at elevated temperature sufficient to carry out applicants objectives. heat exchanger and enters outlet air passage l! which empties into air distribution box 10.

While the various elements are similarly designated, they are not illustrated to the same scale in all figures. For purposes of clarity, those passages through which air circulates have been marked with an arrow and dot. The course of oil circulation is marked by plain arrows. In the air distribution box, as is clearly she generally designated by numeral 14.

While the air'will normally go to exchanger-Q.

l4, under some conditions as will hereinafter be explained, the air from distribution box ID will The intensely heated air leaves the sometimes be routed through outlet I I directly to oil burners I5.

Oil heat exchanger I4 includes a cylindrical metal shell I6 within which is concentrically positioned an oil reservoir I'I. Shell I6 is suitably surrounded by insulation I8 so that heat losses from the shell are reduced to a minimum.

Oil from the usual storage tank is pumped through feed line I9, shown in Figure 2, and this enters a serpentine coil 20 which is positioned in heated air passage 2I of the oil heat exchanger.

As clearly shown in Figure 2, coil 20 is coiled about oil reservoir I! in the heated air passage formed between shell I6 and the oil reservoir I1. The intensely heated air fed from box I through line I3 enters passage 2I at point 22, with the result that oil circulating through coil will be quickly and highly heated. Furthermore, the oil leaving the coil at point 23 and entering oil reservoir I! will further be heated because of efficient interchange between the oil in reservoir I1 and the heated air in passage 2 I, the walls 24 0f the reservoir being of material having a high conductivity.

The oil leaves reservoir I1 through discharge line25 serving burners I 5.

Assuming however that an oil temperature is attained above safe limits, then, in that event, a temperature responsive control 25 is provided for operating an actuating arrangement clearly illustrated in Figure 3 and designated by numeral 2?.

It will be apparent that numerous variations may be employed to accomplish the same result, but for purposes of illustration, applicant shows one arrangement wherein, upon an undesirable rise in oil temperature, a thermostatic element at 26 will cause lever 28 to shift a closure member or disc 29 so that the heated air from exchanger 6 will be stopped from flowing to passage 2| for further oil heating but instead will be routed directly from box I 0 to passage 30 through air outlet II; and. air from passage 30 will feed directly to oil burners I5 through individual air feed lines 3|.

The air from passage 2|, after serving toheat the oil routed through serpentine coil 20 and that inoil reservoir I1, will leave passage 2I through air discharge line 32 and feedinto air passage 30 connected by individual air feed lines to oil burners I5.

The heated oil from reservoir I1 is discharged at point 33 and flows into feed line 34 serving burners I5 through individual oil feed lines 35.

The actuating arrangement in box Ill serves simply and automatically to uncover outlets II and I2 as the case may be, for safe and eificient operation. As shown, the outlet II is normally closed by disc 29 except when the oil temperature reaches an unsafe elevated point whereupon the disc will be shifted to close air outlet I2 and open II.

It will be seen that by this simple and foolproof arrangement, applicant enables heated air to be used to accomplish a multiplicity of desirable purposes in a simple and inexpensive Way. Under normal operating conditions, when maximum atomization is required and elevated air temperatures are desired, the hot air from heat exchanger 6 will be routed directly to oil heat exchanger, I4 where it will elevate the temperature of the oil rapidly and reduce its viscosity to enable speedy and effective atomization. After accomplishing this purpose, it will go directly to the burners, additionally to induce rapid and complete combustion.

On the other hand, should unsafe conditions develop, for any reason, shown by a rise in the temperature or the oil beyond a safe point, then vaporization of oil in the heat exchanger will be prevented and the heating of the oil stopped, by cutting ofi the supply of heated air to exchanger I4, but instead routing it directly from distribution box I0 to air passage 30 serving the burners directly.

When safe conditions are restored, the thermostatic device 26, which reflects the temperature of the oil, will again cause the actuating device to close passage I I and open I2 so that the heated air will again be routed to oil heat exchanger I4 as before described.

It will be appreciated that the usual controls, employed in oil burner systems of this kind, have not been illustrated, since they form no part of this invention. However,applicant does provide some auxiliaries and controls ,to be employed therewith. Thus, as a safety measure, pressure relief valve 36 is provided so that in the event temperature responsive control 26 fails to operate when an unsafe high oil temperature is attained, accompanied by a corresponding rise in oil pressure, relief valve 35 will open and oil permitted to bleed back to the storage tank.

An auxiliary oil heater 31, electrically operated, may be provided if desired within oil reservoir I'I. If, for some reason, auxiliary heating is needed, then responsive to a drop in oil temperature within the reservoir below a minimum point as indicated by any suitable means, this electric heater will automatically cut into service in order to elevate the oil temperature to a desirable'point; and upon a rise in temperature to a set maximum, it will automatically cut out.

Another safety feature is provided in an auxiliary air feed arrangement shown in Figure 1. Thus, if air heat exchanger 6 located in the fire box should for any reason become faulty, then the air for the system will not be routed through the exchanger but instead may be routed directly to the burners. In such case, hand valves 39 and 40 would be closed while valve 4i would be open so that air from intake 5 would bypass exchanger 6 and feed directly to passage 30. When normal conditions are restored, then valve 4I would be closed while valves 39 and 40 reopened so that norma1 routing of the air through exchanger 6 would be resumed.

While applicant has illustrated one form of his invention for utilizing and routing oil and heated air for best promoting efficient combustion, it will be apparent that variations may be employed to accomplish the same or similar purposes. It will be apparent that the use of heated air for elevating the temperature of the oil and reducing its viscosity may be accomplished in similar fashion for reducing the viscosity of other materials and compounds, as in the chemical field; or for ele-,

vating temperatures of viscose fluids and reducing their viscosity whether or not used for combustion purposes.

While I have described a preferred embodiment of the present invention, it will be understood the reservoir placed within the casing, oil burners, a 1 header within the casing connected to the burners and connected to the reservoir adjacent an endof the reservoirl a source of, air under-pressure, a

serpentine coil within said casing disposed about the reservoir, said coil being connected to the reservoir adjacent the other end of the reservoir, means for supplying oil to the other end of the coil, oil supplied to the reservoir passing through the coil, means for preheating the air, means for passing at least a portion of the preheated air in counterflow heat exchange relation to oil in the reservoir and in generally concurrent heat exchange relation to oil in the coil, and means for supplying said preheated air after passage in heat exchange relation with the oil to the burners.

2. An oil burner system according to claim 1 in which means are provided for passing the remainder of the preheated air to the burners Without passage in heat exchange relation with oil in the reservoir and in the coil.

.3. In an oil burner system, a heat exchange structure comprising a housing, a casing extending longitudinally within the housing, a longitudinally extending shell forming an oil reservoir placed within the casing and. spaced therefrom to form a passageway between the shell :and easing surrounding the reservoir for a medium to be placed in heat exchange relation with oil in the reservoir, a serpentine coil placed in the passageway about the reservoir and connected to the reservoir adjacent an end thereof, said reservoir having an outlet adjacent the other end thereof, oil to be supplied to the reservoir passing through said coil in heat exchange relation with medium in the passageway, means to supply oil to the other end of said coil, and means for simultaneously passing preheated medium through the passageway in counterflow relation to oil in said shell and in generally concurrent relation to oil in the coil.

4. In an oil burner system, a heat exchange structure comprising a housing, a casing extending horizontally within the housing, a longitudinally extending shell forming an oil reservoir placed within the casing and spaced therefrom to form a, passageway between the shell and the casing surrounding the reservoir for preheated air to be placed in heat exchange relation with oil in the reservoir, a serpentine coil placed in the passageway about the shell and connected to the reservoir adjacent an end thereof, said reservoir having an outlet adjacent the other end thereof, oil to be supplied to the shell passing through the coil in heat exchange relation with preheated air in the passageway, means to supply oil to the other end of said coil, means for preheating air, and means for simultaneously passing the preheated air through the passageway in counterflow relation to oil in said shell and in generally concurrent relation to oil in the coil, said passageway having an outlet adapted to deliver said air to a burner.

'5. A system according to claim 4 in which a duct is provided adapted to supply said preheated air to a burner without passage in heat exchange relation with the oil, and a control is provided to select the path travelled by the air so that, in response to a predetermined increase in temperature of oil leaving the shell, preheated air will be routed through said duct instead of said passageway.

6. In an oil burner having means for supplying oil thereto, means for preheating air, means for passing the preheated air in generally concurrent and heat exchange relation to oil being supplied to the burner to preheat the oil and for simultaneously passing the preheated air in counterfiow and heat exchange relation to the preheated oil, means for supplying the preheated air after its passage in heat exchange relation with the oil to the burner, a duct for passing the preheated air direct to the burner, and means for automatically selecting the path of air travel so that, in response to a predetermined increase in temperature of oil after its passage in counterfiow relation with the preheated air, preheated air will be routed through said duct instead of said heat exchange means.

7. In apparatus for reducing the viscosity of a viscous material, the combination of a housing, a casing extending longitudinally within the housing, a longitudinally extending shell forming a reservoir for a viscous material placed within the housing and spaced therefrom to form a passageway between the shell and casing surrounding the reservoir for preheated air, means for preheating air, a serpentine coil placed in the passageway about the reservoir and connected to the shell adjacent an end thereof, said reservoir having an outlet adjacent the other end thereof, means for supplying the viscous material to the other end of the coil, means for simultaneously passing the preheated air in counterfiow relation to viscous material in the shell and in generally concurrent heat exchange relation to viscous material in the coil, said passageway having an outlet adapted to deliver said air to a place of use, and control means responsive to an increase or decrease in the temperature of viscous material leaving the shell for decreasing or increasing respectively the flow of preheated air in heat exchange relation with viscous material in the shell.

PAUL TRAUB.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 835,954 Koons Nov. 13, 1906 1,092,212 Hauck Apr. 7, 1914 1,466,186 Pidgeon Aug. 28, 1923 1,554,869 McAndrews Sept. 22, 1925 2,104,974 Dawes Jan. 11, 1938 2,179,846 Finnigan Nov. 14, 1939 2,408,605 Brookes Oct. 1, 1946 

